Lateral medullary syndrome (Wallenberg's Syndrome)

Angiography of the posterior cerebral circulation showing vascular 
supply of the brain stem.

A patient with a right lateral medullary 
syndrome resulting from haemorrhage 
(the white area)

This condition is caused by vascular occlusion or haemorrhage of the lateral medulla and often results from a lesion in the 
posterior inferior cerebellar artery. The signs result from damages to the structures in the lateral medulla which include: 
the sympathetic pathway, Vth cranial nerve, vestibular nuclei, inferior cerebellar peduncle, IXth and Xth cranial nerves.

The patient has a Horner's syndrome with nystagmus, The fast phase is to the side of the Horner's syndrome. There is 
decreased pain and temperature sensation ipsilaterally (sensory component of the trigeminal nerve). The uvula moves to the contralateral side on saying 'Ah' due to palatal weakness. The gag reflex is diminished on the ipsilateral side.

Further examination:

  • mention that you like to examine the cerebellar system
  • examine the pain and temperature sensation (spinothalamic tract) of the contralateral limbs. These are usually impaired.


Can you name a few eponymous syndromes resulting from brainstem infarction with ocular signs.

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